Head slider for disk apparatus

ABSTRACT

A head slider, of a disk apparatus, flying over a rotary magnetic recording disk, having a characteristic less dependent on the atmospheric pressure. The head slider of a disk apparatus comprises: a magnetic element adapted to fly over a magnetic recording medium; a medium opposing surface being formed with, with respect to the direction in which the medium moves, an inflow pad portion at the upstream end and a pair of side rail portions extending downstream from the inflow pad portion, and a center pad at the central part and a pair of side pads on the sides of the center pad and upstream of the center pad at the downstream end of the head slider. The center pad and the side pads are constituted so that a positive pressure generated by the side pads is greater than a positive pressure generated by the center pad.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a head slider for a disk apparatus, orin particular, to a head slider for a disk apparatus comprising amagnetic element adapted to fly over a magnetic recording medium of adisk type to record or reproduce magnetic information between themagnetic element and the magnetic recording medium, wherein the surfaceof the head slider opposed to the medium is formed with, with respect tothe direction in which the medium runs, an inflow pad portion at theupstream end and a pair of side rail portions extending downstream fromthe inflow pad portion, and a center pad at the central part and a pairof side pads on the sides of the center pad and upstream of the centerpad at the downstream end of the head slider.

2. Description of the Related Art

First, a conventional disk apparatus having a magnetic slide headermounted thereon is explained with reference to FIG. 15. FIG. 15 is aplan view of the conventional magnetic disk apparatus 1, in which one ora plurality of disk-type magnetic recording media 3 are mounted on arotatable spindle at predetermined intervals.

A head slider 10 is arranged for each of the obverse and reversesurfaces of each rotary magnetic recording medium 3, and each issupported through a suspension 5 at the end portion of an arm 4 of anactuator swingably supported on a pivot. The head slider 10 is adaptedto be moved, in radial direction (for a seek operation) on each mediumsurface, by a voice coil motor 6.

The head slider 10 of the disk apparatus 1 having the structuredescribed above, as shown in FIG. 16, moves outward or inwardsubstantially radially on the disk-type recording medium while flyingover the medium surface under a positive or negative pressure generatedby the disk-type recording medium 3 rotating at high speed.

In FIG. 16, with the high-speed rotation of the magnetic recordingmedium 3 in the direction along arrow P, an air stream as shown isgenerated in the direction of the arrow P between the magnetic recordingmedium 3 and the head slider 10. Through this air film, under positiveor negative pressure, the head slider 10 flies at a predetermined heightfrom the surface of the magnetic recording medium 3 and is kept inpredetermined spaced relation with the surface of the recording medium3.

In order to realize the high-density packaging of the magnetic recordingmedium 3, the head slider 10 is desirably placed as near to thedisk-type recording medium 3 as possible. Under various conditions,however, a predetermined interval is desirably maintained between themedium surface and the head slider. If the total length of the headslider 10 is 1.25 nm, the flying height t of the head slider 10 from themedium surface is tens and several nm or about 15 nm from the nearestportion of the medium surface where the recording/reproducing magneticelement 7 is mounted.

The head slider 10 of the disk apparatus, having the above-mentionedstructure, flies over the medium surface due to the force generated bythe disk-type recording medium 3 rotating at high speed in the directionof the arrow P in FIG. 17, while at the same time moving (the seekoperation) outward or inward substantially radially over the disk-typerecording medium.

As a result, the running speed of the disk-type recording medium 3relative to the head slider 10 varies depending on whether the headslider 10 runs along the inner peripheral side, the middle peripheralside or the outer peripheral side of the disk-type recording medium 3.At the same time, the direction in which the disk recording medium 3runs with respect to the head slider 3, i.e. the velocity vectors V1,V2, V3 and the directions thereof are varied. Specifically, between theinnermost periphery and the outermost periphery, the running speedchanges about twice and the speed vector changes about 25 degrees.

In designing the head slider 10 of the disk apparatus, therefore, it isimportant to maintain as uniform a flying height t (FIG. 16) of the headslider as possible over the whole periphery of the disk-type recordingmedium 3 and even allowing for a change in velocity or a change in thevelocity vector.

In similar fashion, in the case where the arm 4 (FIG. 15) of theactuator supporting the head slider 10 performs the seek operation, thehead slider 10 mounted at the forward end of the arm 4 moves radiallyinward at some timer and outward at other of the disk-type recordingmedium 3. In the process, the addition of the seek operation to thevelocity vector of the head slider 10 with respect to the recordingmedium 3 changes the direction of the velocity vector (V₄ or V₅) byabout 15 degrees.

With this direction change of the air flow, therefore, the flying heightof the head slider, above the recording medium, is required to bemaintained as uniform as possible.

Further, the device carrying the magnetic disk apparatus, whether it isa stationary computer or a mobile personal computer, is required to withstand operating conditions including a low atmospheric pressure.Generally, the HDD (hard disk drive) requires that the use at highaltitudes is taken into account and therefore has to be operativelyguaranteed even at an altitude of, say, 3000 m above sea level.

Furthermore, taking manufacturing problems such as machining errors andassembly errors into consideration, a robust design is required.

Of all the design problems of the head slider of the disk apparatusdescribed above, this invention is especially intended to provide a headslider for the disk apparatus usable under low atmospheric pressure.

Specifically, the head slider of the conventional disk apparatus posesthe problem that the flying height of the head slider decreases with lowatmospheric pressure. Especially in the case where the head slidersupported at the free end of the arm of the actuator is located on theinner side (inner side) of the disk medium while performing the seekoperation radially of the rotating disk medium, the peripheral speed ofthe disk-type recording medium relative to the head slider is so lowthat a sufficient air-bearing pressure cannot be secured for the headslider. As a result, the flying height decreases considerably with adecrease in atmospheric pressure.

An attempt to secure a head slider having little dependency on theatmospheric pressure, i.e. having a characteristic robust against lowatmospheric pressure encounters the problem of a decreased robustnessagainst a change in peripheral speed. Also, with the decrease inatmospheric pressure, “the pitch angle”, providing an inclination angleof the rotating head slider with respect to the direction upstream ordownstream of the medium, decreases, as does the flying height of thehead slider.

The conventional technique disclosed in Japanese Unexamined PatentPublication No. 2003-323706 related to this invention proposes amagnetic head in which the magnetic core is prevented from coming intocontact with the magnetic recording medium by decreasing the effect ofthe atmospheric pressure on the spacing between the magnetic core andthe magnetic recording medium in the case where the slider body fliesover the magnetic recording medium.

JP-A 2003-323706 disclosed a head slider of a magnetic recordingapparatus, wherein the center pad portion having the magnetic core isformed at the central part of the outflow end (trailing end portion) ofthe surface of the slider body opposed to the medium, and side padportions are formed at the transverse end portions nearer to the inflowend (leading end) than the center pad portion. The total area of thesurfaces of the two side pad portions opposed to the medium is largerthan the area of the surface of the center pad portion opposed to themedium. Each pad portion is formed with a front stepped surface lowerthan the other parts on the leading side.

As described above, an attempt has been made to improved the robustnessof the magnetic head slider against the variations in the atmosphericpressure by adjusting the area of the surfaces of the center pad portionand the side pad portion opposed to the medium. The method disclosed inpatent reference 1, however, takes into consideration only the areas ofthe surface of the center pad portion and the side pad portions inopposed relation to the medium, and fails to sufficiently take intoaccount the amount of the pressure generated by the center pad and theside pads.

In view of this, according to this invention, regardless of the area ofthe surface of the center pad portion and the side pad portions opposedto the medium, the positive pressure generated in the side pad portionsis increased beyond the positive pressure generated in the center padportion thereby to secure the robustness against the variations in theatmospheric pressure. Further, the robustness against the greatervariations in the atmospheric pressure can be improved further bydesigning the shape of the side pad portion appropriately.

SUMMARY OF THE INVENTION

Accordingly, the object of this invention is to provide a head slider,of a disk apparatus, flying over a rotary disk-type magnetic recordingmedium, which has a characteristic less dependent on atmosphericpressure, i.e. is robust against variations in the atmospheric pressureand minimizes the change in the flying height of the head slider evenunder low atmospheric pressure.

According to the present invention, there is provided a head slider of adisk apparatus comprising: a magnetic element adapted to fly over a disktype magnetic recording medium to record or reproduce magneticinformation between the magnetic element and the magnetic recordingmedium; a surface of the head slider opposed to the medium being formedwith, with respect to the direction in which the medium runs, an inflowpad portion at the upstream end and a pair of side rail portionsextending downstream from the inflow pad portion, and a center pad atthe central part and a pair of side pads on the sides of the center padand upstream of the center pad at the downstream end of the head slider;and the center pad and the side pads being constituted so that apositive pressure generated by the side pads is greater than a positivepressure generated by the center pad.

The positive pressure generated by the side pads is greater than thepositive pressure generated by the center pad when the head slider islocated in an inner peripheral area of the magnetic recording medium.

In a head slider of the disk apparatus as mentioned above, at least oneof the side pads has an air-bearing surface and a stepped surface, aheight thereof is smaller than that of the air bearing surface, one ofthe air-bearing surface and the stepped surface has a longitudinalextension and a traverse extension to define a substantially L-shapedstructure.

At least one of the side pads has the longitudinal extension of thesubstantially L-shaped structure, located in an outer peripheral sidewith respect to the magnetic recording medium, so that the substantiallyL-shaped structure is opened to an inner peripheral side with respect tothe magnetic recording medium.

In a head slider of the disk apparatus, as mentioned above, each of theinflow pad portion, the center pad and the side pads has an air-bearingsurface and a stepped surface, the height thereof being smaller thanthat of the air bearing surface, at least one of the side rail portionsis connected with the corresponding and at least the side rail portionis arranged nearer to a traverse center of the head slider by 10 μm ormore from a corresponding side edge of the head slider.

The side rail portions are constituted so that a connecting portion withthe inflow pad portion or a connecting portion with the side pad isdefined by an obtuse angle.

In a head slider of the disk apparatus as mentioned above, the centerpad has an air-bearing surface and a stepped surface at an outflow sideof the air-bearing surface and has a height smaller than that of the airbearing surface, the air bearing surface has a traverse extension at anoutflow area of the center pad and front longitudinal extensions atrespective sides of the center pad to define a substantially U-shapedstructure, and a stepped surface has an immediately front area of theair bearing surface and a central protrusion extending upstream of thehead slider form the immediately front area.

A connecting portion of the central protrusion of the stepped surfaceis, with respect to the immediately front area, provided with achamfered portion at an outer side with respect to the recording medium.

In a head slider of the disk apparatus as mentioned above, a negativepressure area is defined as an area surrounded by the inflow pad portionand side rail portions; the negative pressure area comprises an innerperipheral negative pressure area and an outer peripheral negativepressure area with respect to the recording medium, and the innerperipheral negative pressure area is extended more toward the inflowedge of the head slide than the outer peripheral negative pressure area.

In a head slider of the disk apparatus as mentioned above, a negativepressure area is defined an area surrounded the inflow pad portion andside rail portions; a starting point of the negative pressure area isdefined by a point within 25 percent from an inflow edge of the headslider with respect the entire length of the head slider.

In a head slider of the disk apparatus as mentioned above, the inflowpad portion has an air-bearing surface transversely extending along anupstream end portion of the head slider and a stepped surface having aheight smaller than that of the air-bearing surface and transverselyextending between the air-bearing surface an upstream edge of the of thehead slider, and the stepped surface is provided with at least twoprojections having a height similar to that of the air-bearing surface.

BRIEF DESCRIPTION OF THE INVENTION

FIG. 1 is a plan view showing a first embodiment of the invention;

FIG. 2 is a plan view showing a second embodiment of the invention;

FIG. 3 is a plan view showing a third embodiment of the invention;

FIG. 4 is a plan view showing a fourth embodiment of the invention;

FIG. 5 is a plan view showing a fifth embodiment of the invention;

FIG. 6 is a plan view showing a sixth embodiment of the invention;

FIG. 7 is a plan view showing a seventh embodiment of the invention;

FIG. 8 is a plan view showing an eighth embodiment of the invention;

FIG. 9 is a plan view showing a ninth embodiment of the invention;

FIG. 10 is a plan view showing a tenth embodiment of the invention;

FIG. 11 is a plan view showing an 11th embodiment of the invention;

FIG. 12 is a plan view showing a 12th embodiment of the invention;

FIG. 13 is a plan view showing a 13th embodiment of the invention;

FIG. 14 is a plan view showing a 14th embodiment of the invention;

FIG. 15 is a plan view schematically showing a disk apparatus;

FIG. 16 is a side view of a head slider of a disk apparatus;

FIG. 17 is a diagram showing the relation between the position of thehead slider and the flow velocity vectors;

FIG. 18 is a diagram showing the relation between the seek operation ofthe head slider and the flow velocity vectors; and

FIG. 19 is a perspective view as taken from the surface of the headslider opposed to the medium.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the invention are described in detail below withreference to the accompanying drawings.

FIGS. 1 to 14 are plan views taken from that side of a head slider of adisk apparatus, according to each embodiment of the invention, which isin opposed relation to a medium. FIG. 19 is a perspective view of thehead slider according to the invention taken from the surface thereofopposed to the magnetic recording medium, or especially, the unevensurface of the slider opposed to the medium. In FIG. 19, the heightsfrom the bottom surface B to the air-bearing surface (ABS) and to thestepped surface D are exaggerated.

In FIG. 19, the head slider body 10 is formed of an appropriate ceramicmaterial such as alumina titanium carbide (AlTiC) and is fabricated by aconventionally well-known method such as ion milling or ion etching. Thehead slider body 10 assumes a substantially rectangular plan view takenfrom the side thereof opposed to the medium. With respect to thedirection P in which the magnetic recording medium rotates, the headslider body 10 includes an inflow end 10 a constituting an upstreamtransverse edge, a outflow end 10 b constituting a rear transverse edgeand longitudinal side edges 10 c, 10 d.

In order to secure the required air-bearing force between the surface ofthe head slider 10 opposed to the medium and the rotating magneticrecording medium, minuscule unevenesses are formed on the particularopposed surface of the head slider 10 to thereby control the pressure.Especially, a sophisticated air-bearing function is realized by properlycontrolling the combinations of the positive and negative pressuresgenerated by the minuscule unevenesses.

As shown in FIG. 19, the head slider 10 has an uneven surface in threesteps opposed to the medium. In this specification, the surface Bprimarily forming a negative pressure surface farthest from the surfaceof the magnetic recording medium is defined as “the bottom surface”, thesurface A primarily forming a positive pressure surface located nearestto the surface of the magnetic recording medium is defined as “theair-bearing surface (ABS)”, and the surface D slightly stepped down fromthe air-bearing surface A is defined as “the stepped surface”. The deptha from the air-bearing surface A to the bottom surface B is about 1 to 3μm, and the depth b from the air-bearing surface A to the steppedsurface D is about 0.1 to 0.3 μm.

The air-bearing surface A includes an inflow pad portion A(1), locatedin proximity to and in slightly spaced relation with the upstream end,extending over the entire width of the head slider body 10 transverse tothe direction P in which the medium rotates. A center pad portion A(2)is located at the central part of the downstream end along the directionP. Further, side pad portions A (3), A(4) are located on both sidesslightly upstream of the center pad portion A(2).

On the other hand, the stepped surface D includes, in terms of directionP in which the medium runs, an inflow-side stepped surface D(1)extending over the entire transverse area forward of the inflow padportion A(1), side rail portions D(5), D(6) extending downstream alongthe two side edges of the head slider from the inflow pad portion A(1),and a center stepped surface D(2) and side stepped surfaces D(3), D(4)arranged forward of the center pad portion A(2) and the side padportions A(3), A(4).

The surface area of the head slider 10, opposed to the medium, otherthan the air-bearing surface A and the stepped surface D constitutes thebottom surface B. Especially, the central area of the bottom surface Bof the head slider opposed to the medium which is defined by the inflowpad portion A(1), the side rail portions D(5), D(6), the center padportion A(2), the stepped surface D(2), the side pad portions A(3), A(4)and the stepped surfaces D(3), D(4) makes up a negative pressureportion.

The air-bearing force of the head slider 10 against the recording mediumsurface can be controlled by changing various parameters including theshape and area of the air-bearing surface A and the stepped surface D ofthe head slider 10 opposed to the medium.

Next, the air-bearing surface A and the stepped surface D of the headslider 10, opposed to the medium, according to various embodiments ofthe invention are explained with reference to FIGS. 1 to 14. In thesediagrams, as defined above, the air-bearing surface A is hatched, thestepped surface D dotted and the bottom surface B outlined.

FIG. 1 is a plan view showing the surface of the head slider opposed tothe medium according to a first embodiment of the invention. In FIG. 1,reference numeral 11 designates an inflow end by way of which the airflows in and numeral 12 an outflow end by way of which the air flowsout. Numeral 13 designates a center pad portion, and numerals 14, 15side pad portions. According to the first embodiment, the pressure(positive pressure) generated by the two side pad portions 14, 15 is setlarger than the pressure (positive pressure) generated by the center padportion 13. As a result, the flying height is prevented from beingdecreased extremely by a drop in atmospheric pressure.

Specifically, in addition to the area of the air-bearing surface A ofthe center pad portion 13 and the area of the air-bearing surface A ofthe side pad portions 14, 15, such factors as the size, shape,arrangement of the center pad portion 14 and the side pad portions 14,15 and the corresponding size, shape, arrangement and other physicalconfigurations of the stepped surface D are variously changed. In thisway, the pressure generated by the two side pad portions 14, 15 can beset larger than the pressure generated by the center pad portion 13. Themagnitude of the pressure obtained, on the surface of the head slideropposed to the medium, by factors including the size, shape andarrangement, is specifically determined by computer simulation.

FIG. 2 is a plan view showing the surface of the slider head opposed tothe medium according to a second embodiment of the invention. Numeral 21designates an inflow end by way of which the air flows in, and numeral22 an outflow end by way of which the air flows out. Numeral 23designates a center pad portion, and numerals 24, 25 side pad portions.According to the second embodiment, in the case where the head slider islocated radially inside of the recording medium, the air flows from thelower left portion to the upper right portion in FIG. 2 in the directionalong arrow Q (in reverse relation with the case of FIG. 17). Thus, asshown in FIG. 2, the front edge of the air-bearing surface A of the sidepad portions 24, 25 is directed inward to increase the pressuregenerated by the air flow along the direction of arrow Q. As a result,as long as the head slider is located radially inside of the magneticrecording medium, the pressure generated by the side pad portions 24, 25is increased.

Specifically, a higher pressure (positive pressure) is generated by theside pad portions 24, 25 when the head slider is located in the innerperipheral area than in the outer peripheral area of the magneticrecording medium. This prevents an extreme decrease in the flying heightof the head slider which otherwise might be caused by a drop inatmospheric pressure in the case where the head slider is locatedradially inside of the magnetic recording medium and the relative speedbetween the head slider and the magnetic recording medium is reduced.

FIG. 3 is a plan view showing the surface of the head slider opposed tothe medium according to a third embodiment of the invention. Numeral 31designates an inflow end by way of which the air flows in, and numeral32 an outflow end by way of which the air flows out. Numeral 33designates a center pad portion, and numerals 34, 35 side pad portions.According to the third embodiment, the air-bearing surface A of each ofthe side pad portions 34, 35 is formed into a substantially L-shapedstructure by the rear transverse extension A1 and the longitudinalextension A2. The stepped surface D is extended to the central edge andthe upstream edge defined by the air-bearing surface A1, A2 of thesubstantially L-shaped structure. Thus, the air-bearing surfaces A ofthe side pad portions 34, 35 of the stepped surface D are mutuallydirected toward the center as shown in FIG. 3. Specifically, eachlongitudinal extension A2 is located nearer to the side edge of theslider body than the corresponding stepped surface. As a result, the airflowing in along the direction of arrow P is concentrated effectively bythe side pad portions, as banks, so that the pressure generated by theside pad portions 34, 35 increases. Thus, an extreme decrease in theflying height of the head slider, which might otherwise be caused by thedrop in atmospheric pressure, is prevented.

FIG. 4 is a plan view showing the surface of the head slider opposed tothe medium according to a fourth embodiment of the invention. Numeral 41designates an inflow end by way of which the air flows in, and numeral42 an outflow end by way of which the air flows out. Numeral 43designates a center pad portion, and numerals 44, 45 designate side padportions. According to the fourth embodiment having a similarconfiguration to the third embodiment, the air-bearing surface A of theside pad portions 34, 35 according to the third embodiment is formedinto a substantially L-shaped structure by the rear transverse extensionAl and the longitudinal extension A2. The stepped surface D is extendedto the central edge and the upstream edge of the air-bearing surface A1of the substantially L-shaped structure. In the case where the headslider is located on the inner peripheral side of the magnetic recordingmedium, the air flows in the direction of arrow Q from the lower leftportion toward the upper right portion in FIG. 4.

Thus, the longitudinal extension A2 of the air-bearing surface A of thesubstantially L-shaped structure of the side pad portion 44 locatedinside is arranged nearer to the outer periphery of the recordingmedium, i.e. nearer to the center of the head slider in the steppedsurface D as shown in FIG. 4. As a result, especially in the case wherethe head slider is located radially inside of the magnetic recordingmedium, the air flowing in the direction along arrow Q is received bythe substantially L-shaped air-bearing surfaces A of the side padportions 44, 45, thereby increasing the pressure generated by the sidepad portions 44, 45.

Specifically, the side pad portions 44, 45 generate a higher pressure(positive pressure) in the case where the head slider is located moreinside than outside radially of the magnetic recording medium. Thus, itis possible to prevent an extreme decrease in the flying height of thehead slider, which otherwise might be caused by the drop in atmosphericpressure, in the case where the head slider is located radially insideof the magnetic recording medium where the relative speed is reducedbetween the head slider and the magnetic recording medium.

FIG. 5 is a plan view showing the surface of the head slider opposed tothe medium according to a fifth embodiment of the invention. Numeral 51designates an inflow end by way of which the air flows in, and numeral52 an outflow end by way of which the air flows out. Numeral 53designates a center pad portion, and numerals 54, 55 side pad portions.According to the fifth embodiment, the stepped surface D extendingforward of the air-bearing surface A of the side pad portions 54, 55 isformed into a substantially L-shaped structure by the rear transverseextension D1 and the longitudinal extension D2. The longitudinalextensions D2 of the substantially L-shaped structure of the steppedsurfaces D of the two side pad portions 54, 55 are arranged on the outerperipheral side of the head slider. Thus, the air stream flowing inalong arrow P and reaching the front part of the side pad portions 54,55 is directed inward by the stepped surface D of the substantiallyL-shaped structure of the side pad portions 54, 55. The air streamsflowing into the head slider in the directions of arrows R are alsocontrolled.

In this way, the air stream is effectively concentrated with the steppedsurface D2 of the substantially L-shaped structure as a bank, therebyincreasing the pressure generated by the side pad portions 54, 55. As aresult, the flying height of the head slider is prevented from extremelydecreasing due to the drop in the atmospheric pressure.

FIG. 6 is a plan view showing the surface of the head slider opposed tothe medium according to a sixth embodiment of the invention. Numeral 61designates an inflow end by way of which the air flows in, and numeral62 an outflow end by way of which the air flows out. Numeral 63designates a center pad portion, and numerals 64, 65 side pad portions.The sixth embodiment has a similar configuration to the fifth embodimentin that the stepped surface D extending on the front of the air-bearingsurface A of each of the side pad portions 64, 65 is formed into asubstantially L-shaped structure by the rear transverse extension D1 andthe longitudinal extension D2. Nevertheless, the longitudinal extensionsD2 of the substantially L-shaped structure of the stepped surfaces D ofthe two side pad portions 64, 65 are both arranged on the outerperipheral side of the magnetic recording medium.

With this structure, in the case where the head slider is locatedradially inside of the magnetic recording medium, the air flows in thedirection along arrow Q from the lower left portion toward the upperright portion in FIG. 6. By arranging the longitudinal extension D2 onthe front of the substantially L-shaped stepped surface D of each of theside pad portions 64, 65 on the outer peripheral side of the magneticrecording medium as shown in FIG. 6, therefore, the air flowing in thedirection along arrow Q is received by the substantially L-shapedstepped surface D of the side pad portions 64, 65 in the case where thehead slider is located radially inside of the magnetic recording medium.Therefore, the pressure generated by the side pad portions 64, 65 isincreased. As a result, it is possible to prevent the extreme decreasein the flying height of the head slider which otherwise might be causedby the drop in atmospheric pressure in the case where the head slider islocated radially inside the magnetic recording medium where the relativespeed is reduced between the head slider and the magnetic recordingmedium.

FIG. 7 is a plan view showing the surface of the head slider opposed tothe medium according to a seventh embodiment of the invention. Numeral71 designates an inflow end by way of which air flows in, and numeral 72an outflow end by way of which air flows out. Numeral 3 designates acenter pad portion, numerals 74, 75 side pad portions, and numerals 76,77 side rail portions. According to the seventh embodiment, the siderail portions 76, 77 formed as a stepped surface D are arranged nearerto the transverse center of the head slider by W (10 μm or more, forexample) from the side edges 10 c, 10 d thereof, respectively. Also, theupstream end of each of the side rails 76, 77 is coupled to theair-bearing surface A of the inflow pad portion 710, while eachdownstream end thereof is connected to the stepped surfaces of the sidepad portions 74, 75. Thus, the air-bearing surface A of the inflow padportion 710, the side pad portions 76, 77 and the stepped surface of theside pad portions 74, 75 are longitudinally connected.

According to the seventh embodiment, as described above, the side rails76, 77 are arranged nearer to the transverse center of the head sliderby W (10 μm or more, for example) from the side edges 10 c, 10 d of thehead slider while at the same time being connected to the air-bearingsurface A of the inflow pad portion 710, As a result, the side padportions 76, 77 constitute banks whereby the air flowing in thedirection of arrow P is concentrated effectively. Especially, thisstructure exhibits a greater effect of concentrating the air streams Rthat have circumvented inside of the head slider. As a result, the sidepad portions 74, 75 generate a higher pressure, and the extreme decreasein the flying height of the head slider, due to a drop in atmosphericpressure, is prevented.

FIG. 8 is a plan view showing the surface of the head slider opposed tothe medium according to an eighth embodiment of the invention. Numeral81 designates an inflow end by way of which the air flows in, andnumeral 82 an outflow end by way of which the air flows out. Numeral 83designates a center pad portion, numerals 84, 85 side pad portions,numerals 86, 87 side rail portions, and numerals 88, 89 the angles atwhich the side rail portion and the corresponding side pad portion areconnected to each other. According to the eighth embodiment, as in theseventh embodiment, the side rail portions 86, 87 formed as a steppedsurface D are arranged nearer to the transverse center of the headslider by W (10 μm or more, for example) from the side edges 10 c, 10 dthereof, respectively. Thus, the air-bearing surface A of the inflow padportion 810, the side rail portions 86, 87 and the stepped surface ofthe side pad portions 84, 85 are continuously connected to each other.

According to the eighth embodiment, however, the angle of eachconnecting portion between the side rail portions 86, 87 and the steppedsurface of each of the side pad portions 84, 85 is rendered obtuse onthe side nearer to the outer periphery of the magnetic head slider byforming a chamfered portion. These chamfered portions are also formed asstepped surfaces. In this way, according to the eighth embodiment, theside rail portions 86, 87 are arranged nearer to the transverse centerof the head slider by size w (10 μm or more, for example) from the headslider side edges 10 c, 10 d while at the same time being connected tothe air-bearing surface A of the inflow pad portion 810. Further, theangles 88, 89 of the connecting portion between each of the side railportions 86, 87 and the stepped surface of each of the side pad portions84, 85 are rendered obtuse on the side nearer to the outer periphery ofthe head slider. As in the seventh embodiment, therefore, the side railportions 86, 87 make up banks, so that the air flowing in along thedirection of arrow P (or inward of the head slider along the directionof arrow R) is effectively concentrated. Also, when the head slider isbeing machined, stands by for operation against the recording medium oris flying, the chance of dust or dirt being deposited at or around theside rail portions 86, 87 is reduced. Especially when the head sliderflies, the dust and dirt attached to the surface of the magneticrecording medium rotating at high speed is possibly preventedeffectively from flowing into the head slider together with the airflowing in along the direction of arrow R.

FIG. 9 is a plan view showing the surface of the head slider opposed tothe medium according to a ninth embodiment of the invention. Numeral 91designates an inflow end by way of which the air flows in, and numeral92 an outflow end by way of which the air flows out. Numeral 93designates a center pad portion, and numerals 94, 95 side pad portions,numerals 96, 97 side rail portions, and numerals 98, 99 angles of theconnecting portion between the side rail portions and the inflow padportion 910. According to the ninth embodiment, as in the seventhembodiment, the side rail portions 96, 97 formed as a stepped surface Dare arranged nearer to the transverse center of the head slider by sizew (10 μm or more, for example) from the side edges 10 c, 10 d of thehead slider, while at the same time longitudinally connecting theair-bearing surface A of the inflow pad portion 910, the side railportions 96, 97 and the stepped surface of the side pad portions 94, 95.

In the ninth embodiment, however, chamfered portions 921, 922 are formedto assure an obtuse angle, on the side nearer to the outer periphery ofthe head slider, of the connecting portion between the side railportions 96, 97 and the air-bearing surface A of the inflow pad portion910. The chamfered portions 921, 922 are also formed as a steppedsurface. In this way, according to the ninth embodiment, the side railportions 86, 87 are arranged nearer to the transverse center of the headslider by size W (10 μm or more, for example) from the head slider sideedges 10 c, 10 d while at the same time being connected to theair-bearing surface A of the inflow pad portion 810. Further, the outerangles 88, 89 of the connecting portion between the side rail portions86, 87 and the inflow pad portion 910 are rendered obtuse. Like in theseventh embodiment, therefore, the side rail portions 86, 87 make upbanks, so that the air flowing in along the direction of arrow P (orinward of the head slider along the direction of arrow R) is effectivelyconcentrated. Also, when the head slider is being machined, standing byfor operation against the recording medium or is flying, the chance ofdust or dirt being deposited at or around the side rail portions 86, 87is reduced. Especially when the head slider is flying, the dust and dirtattached to the surface of the magnetic recording medium rotating athigh speed is effectively prevented from flowing into the head slidertogether with the air flowing in the direction of arrow R.

In the embodiments shown in FIGS. 7 to 9, the size W is 10 μm or more.The head slider proper, depending on the type thereof, has the totallength of about 1.25 mm and the total width of about 1.0 mm or the totallength of about 0.85 mm and the total width of about 0.70 mm, forexample.

FIG. 10 is a plan view showing the surface of the head slider opposed tothe medium according to a tenth embodiment of the invention. Numeral 101designates an inflow end by way of which the air flows in, and numeral102 an outflow end by way of which the air flows out. Numeral 103designates a center pad portion, and numerals 104, 105 side padportions, and numerals 106, 107 portions of a channel-shaped structureformed as an air-bearing surface A of the center pad portion 103. Thistenth embodiment has the feature in the structure of the center padportion 103. Specifically, the part of the center pad portion 103nearest to the recording medium surface constituting the air-bearingsurface A is formed in the shape of a channel together with the reartransverse extension and the longitudinal extensions on the two sides inthe front part. Also, in the area in front of the air-bearing surface Aof the center pad portion 103, a stepped surface D lower than theair-bearing surface A is configured of an area 109 immediately beforethe air-bearing surface A and a central protrusion 108 extendingupstream of the head slider from the area 109.

The employment of this structure can realize robustness against theperipheral velocity of the magnetic recording medium. Also, in the casewhere only the air-bearing surface A of the center pad portion 103 isformed substantially in the shape of a channel with longitudinal padportions 106, 107, the head slider might fly with the central partthereof radially rising in profile. According to this embodiment,however, the provision of the central protrusion 108 extending forwardof the stepped surface D exhibits the special effect of concentratingthe air flowing into the head slider in the directions of arrows S, sothat the radial profile of the flying head slider is flattened.

FIG. 11 is a plan view showing the surface of the head slider opposed tothe medium according to an 11th embodiment of the invention. Numeral 111designates an inflow end by way of which the air flows in, and numeral112 an outflow end by way of which the air flows out. Numeral 113designates a center pad portion, and numerals 114, 115 side padportions, and numerals 116, 117 parts of a channel-shaped structureformed as an air-bearing surface A of the center pad portion. Numeral118 designates a central protrusion formed as a stepped surface of thecenter pad portion, and numeral 119 a chamfered portion formed as astepped surface at the outer root downstream of the central protrusion118. The 11th embodiment, though analogous to the tenth embodiment shownin FIG. 10, is different from the tenth embodiment in that the chamferedportion is formed as a stepped surface at the outer root constitutingthe downstream end of the central protrusion 118. As a result, thedependency on atmospheric pressure can be somewhat reduced in the casewhere the head slider is located radially outside of the magneticrecording medium. Specifically, this structure prevents the head sliderfrom flying too high due to an excessive dependency of the head slideron the atmospheric pressure in the case where the head slider is locatedradially outside of the magnetic recording medium.

FIG. 12 is a plan view showing the surface of the head slider opposed tothe medium according to a 12th embodiment of the invention. Numeral 121designates an inflow end by way of which the air flows in, and numeral122 an outflow end by way of which the air flows out. Numeral 123designates a center pad portion, numerals 124, 125 side pad portions,numeral 126 an inner negative pressure area, and numeral 127 an outernegative pressure area. According to the 12th embodiment, the negativepressure area 126 of the head slider inward of the recording medium isexpanded toward the inflow end 121 of the head slider more than theouter negative pressure area 127.

Specifically, the length of the longitudinal size of the stepped surface129 on the most inflow end side of the inflow pad portion is minimizedand, at the same time, the rear edge of the air-bearing surface A of theinflow pad portion is located as forward as possible. In this way, thenegative pressure area 126 of the head slider radially inside of therecording medium is enlarged as far as possible. In order to prevent thenegative pressure area 127 on the outer peripherally side of the headslider from being increased excessively, on the other hand, a steppedsurface 128(D) is extended only on the outer peripheral side of therecording medium on the rear of the air-bearing surface A of the inflowpad portion. By expanding the inside negative pressure area 126 in thisway, even in the case where a high pressure is generated by the innerside pad portion 124, the variation in the “rolling” direction of thehead slider due to the radial position of the recording medium, i.e. thetransversal inclination of the head slider as viewed from the front, canbe minimized.

FIG. 13 is a plan view showing the surface of the head slider opposed tothe medium according to a 13th embodiment of the invention. Numeral 131designates an inflow end by way of which the air flows in, and numeral132 an outflow end by way of which the air flows out. Numeral 133designates a center pad portion, numerals 134, 135 side pad portions andnumeral 136 a negative pressure area. According to the 13th embodiment,the negative pressure area 136 is formed of not more than 25% of thetotal longitudinal length of the head slider from the inflow end 131 ofthe head slider. In other words, the distance L2 from the inflow end 131to the starting point of the negative pressure area 136 is set at notmore than 25% of the length L1 of the head slider from the inflow end131 to the outflow end 132.

As a result, the negative pressure area 136 can be widened further, andthe change in pitch angle of the head slider due to the variation inatmospheric pressure can be reduced to stabilize the position of thehead slider.

FIG. 14 is a plan view showing the surface of the head slider opposed tothe medium according to a 14th embodiment of the invention. Numeral 141designates an inflow end by way of which the air flows in, and numeral142 an outflow end by way of which the air flows out. Numeral 143designates a center pad portion, numerals 144, 145 side pad portions andnumerals 146, 147 inner and outer protrusions, respectively, in theinflow pad portion. According to the 14th embodiment, the protrusions146, 147 constituting the air-bearing surface are formed in the insideand outside areas of the front stepped surface of the air-bearingsurface A of the inflow pad portion. These protrusions 148, 149 arelocated near to the side edges of the head slider at the positionssomewhat nearer to the center than the side rail portions 148, 149.Also, as shown in FIG. 14, the protrusions 146, 147 extend forwardsubstantially to the inflow end 141 from the inflow pad portion 140formed as an air-bearing surface.

As described above, according to the 14th embodiment, the provision ofthe protrusions 146, 147 constituting the air-bearing surfaces in theneighborhood of the side edges of the inflow end 141 improves thedependency of the pitch angle of the head slider on the peripheralvelocity.

The head slider of the disk apparatus according to various embodimentsof the invention is described above with reference to the accompanyingdrawings. The invention, however, is not limited to these embodiments,but may take various other forms and may be modified and changedvariously without departing from the spirit and scope of the invention.

It will thus be understood from the foregoing description that,according to the invention, there is provided a head slider of a diskapparatus in various shapes whereby the change in the flying height dueto the change in atmospheric pressure is reduced, so that even in thecase where the atmospheric pressure changes with an altitude above sealevel from zero to 4200 m, for example, the flying height of the headslider can be reduced to 0 nm effectively. Further, the flying height ofthe head slider can be increased within the altitude range of zero to4200 m. Also, the dependency of the flying height of the head slider onthe peripheral velocity and the dependency of the pitch angle can beimproved.

1. A head slider of a disk apparatus comprising: a magnetic elementadapted to fly over a disk type magnetic recording medium to record orreproduce magnetic information between the magnetic element and themagnetic recording medium; a surface of the head slider opposed to themedium being formed with, with respect to the direction in which themedium runs, an inflow pad portion at the upstream end and a pair ofside rail portions extending downstream from the inflow pad portion, anda center pad at the central part and a pair of side pads on the sides ofthe center pad and upstream of the center pad at the downstream end ofthe head slider; and the center pad and the side pads being constitutedso that a positive pressure generated by the side pads is greater than apositive pressure generated by the center pad.
 2. A head slider as setforth in claim 1, wherein the positive pressure generated by the sidepads is greater than the positive pressure generated by the center padwhen the head slider is located in an inner peripheral area of themagnetic recording medium.
 3. A head slider of a disk apparatuscomprising: a magnetic element adapted to fly over a disk type magneticrecording medium to record or reproduce magnetic information between themagnetic element and the magnetic recording medium; a surface of thehead slider opposed to the medium being formed with, with respect to thedirection in which the medium runs, an inflow pad portion at theupstream end and a pair of side rail portions extending downstream fromthe inflow pad portion, and a center pad at the central part and a pairof side pads on the sides of the center pad and upstream of the centerpad at the downstream end of the head slider; and at least one of theside pads having an air-bearing surface and a stepped surface, theheight thereof being smaller than that of the air bearing surface, oneof the air-bearing surface and the stepped surface having a longitudinalextension and a traverse extension to define a substantially L-shapedstructure.
 4. A head slider as set forth in claim 3, wherein at leastone of the side pads has the longitudinal extension of the substantiallyL-shaped structure, located in an outer peripheral side with respect tothe magnetic recording medium, so that the substantially L-shapedstructure is opened to an inner peripheral side with respect to themagnetic recording medium.
 5. A head slider of a disk apparatuscomprising: a magnetic element adapted to fly over a disk type magneticrecording medium to record or reproduce magnetic information between themagnetic element and the magnetic recording medium; a surface of thehead slider opposed to the medium being formed with, with respect to thedirection in which the medium runs, an inflow pad portion at theupstream end and a pair of side rail portions extending downstream fromthe inflow pad portion, and a center pad at the central part and a pairof side pads on the sides of the center pad and upstream of the centerpad at the downstream end of the head slider; and each of the inflow padportion, the center pad and the side pads having an air-bearing surfaceand a stepped surface, a height thereof being smaller than that of theair bearing surface, at least one of the side rail portions beingconnected with the corresponding and at least the side rail portionbeing arranged nearer to a traverse center of the head slider by 10 Amor more from a corresponding side edge of the head slider.
 6. A headslider as set forth in claim 5, wherein the side rail portions areconstituted so that a connecting portion with the inflow pad portion ora connecting portion with the side pad is defined by an angle of obtuse.7. A head slider of a disk apparatus comprising: a magnetic elementadapted to fly over a disk type magnetic recording medium to record orreproduce magnetic information between the magnetic element and themagnetic recording medium; a surface of the head slider opposed to themedium being formed with, with respect to the direction in which themedium runs, an inflow pad portion at the upstream end and a pair ofside rail portions extending downstream from the inflow pad portion, anda center pad at the central part and a pair of side pads on the sides ofthe center pad and upstream of the center pad at the downstream end ofthe head slider; and the center pad having an air-bearing surface and astepped surface at an outflow side of the air-bearing surface and havinga height smaller than that of the air bearing surface, the air bearingsurface having a traverse extension at an outflow area of the center padand front longitudinal extensions at respective sides of the center padto define a substantially U-shaped structure, and a stepped surfacehaving an immediately front area of the air bearing surface and acentral protrusion extending upstream of the head slider form theimmediately front area.
 8. A head slider as set forth in claim 7,wherein a connecting portion of the central protrusion of the steppedsurface is with respect to the immediately front area is provided with achamfered portion at an outer side with respect to the recording medium.9. A head slider of a disk apparatus comprising: a magnetic elementadapted to fly over a disk type magnetic recording medium to record orreproduce magnetic information between the magnetic element and themagnetic recording medium; a surface of the head slider opposed to themedium being formed with, with respect to the direction in which themedium runs, an inflow pad portion at the upstream end and a pair ofside rail portions extending downstream from the inflow pad portion, anda center pad at the central part and a pair of side pads on the sides ofthe center pad and upstream of the center pad at the downstream end ofthe head slider; a negative pressure area defined an area surrounded theinflow pad portion and side rail portions; the negative pressure areacomprising an inner peripheral negative pressure area and an outerperipheral negative pressure area with respect to the recording medium,and the inner peripheral negative pressure area being more extendedtoward the inflow edge of the head slide than the outer peripheralnegative pressure area.
 10. A head slider of a disk apparatuscomprising: a magnetic element adapted to fly over a disk type magneticrecording medium to record or reproduce magnetic information between themagnetic element and the magnetic recording medium; a surface of thehead slider opposed to the medium being formed with, with respect to thedirection in which the medium runs, an inflow pad portion at theupstream end and a pair of side rail portions extending downstream fromthe inflow pad portion, and a center pad at the central part and a pairof side pads on the sides of the center pad and upstream of the centerpad at the downstream end of the head slider; a negative pressure areadefined an area surrounded the inflow pad portion and side railportions; a starting point of the negative pressure area being definedby a point within 25 percent from an inflow edge of the head slider withrespect the entire length of the head slider.
 11. A head slider of adisk apparatus comprising: a magnetic element adapted to fly over a disktype magnetic recording medium to record or reproduce magneticinformation between the magnetic element and the magnetic recordingmedium; a surface of the head slider opposed to the medium being formedwith, with respect to the direction in which the medium runs, an inflowpad portion at the upstream end and a pair of side rail portionsextending downstream from the inflow pad portion, and a center pad atthe central part and a pair of side pads on the sides of the center padand upstream of the center pad at the downstream end of the head slider;the inflow pad portion having an air-bearing surface transverselyextending along an upstream end portion of the head slide and a steppedsurface having a height smaller than that of the air-bearing surface andtransversely extending between the air-bearing surface an upstream edgeof the of the head slider, and the stepped surface being provided withat least two projections having heights similar to that of theair-bearing surface.